The present disclosure relates to a photoelectric conversion element such as a PIN photodiode used for e.g. radiation imaging device and optical touch sensor, and a method for manufacturing the same.
The PIN photodiode is used as a photoelectric conversion element in radiation imaging device, optical touch panel, etc. This PIN (Positive Intrinsic Negative) photodiode has a structure in which a so-called i-type semiconductor layer is interposed between a p-type semiconductor layer and an n-type semiconductor layer, and a signal charge with the amount of charge dependent on the amount of incident light can be extracted.
Such a photodiode is desired to have further enhanced optical sensitivity and various proposals have been made for this desire (refer to e.g. Japanese Patent Laid-open No. 2000-156522). This patent document discloses a photoelectric conversion device in which a semiconductor layer in the photoelectric converter is extended to the transistor part and this extended part is used as a light blocking layer to thereby ensure a high aperture ratio and enhance the pattern accuracy to achieve enhanced sensitivity.